//ArrayList
  public ArrayList<String> merge(String[] words, String[] more) {
    ArrayList<String> out = new ArrayList<String>();
    for(String word:words)
      out.add(word);
    for(String m:more)
      out.add(m);
    return out;  
  }
  
//StringBuffer
    //First the Problem of String Joining:  Running time is O(xn^2); n words, each word x characters.
    public String joinStrings(String[] words) {
      String out = "";
      for(String word:words)
        out = out+word;
      
      return out;
    }
    
    //Second the advantage the StringBuffer offers: It creates an array of all the strings, only copy them back to ONE when needed.
    public StringBuffer joinWords(String[] words) {
      StringBuffer out = new StringBuffer();
      for(String word:words) 
        out.append(word);    
          
      return out.toString();
    }
    